One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,7)(5,8)(9,10,13,16)(11,17,19,14)(12,15,20,22)(18,23,24,21)(28,36)(30,39)(32,37)(34,38)(1,3,5,4)(2,6,8,7)(9,11,13,19)(10,14,16,17)(12,18,20,24)(15,21,22,23)(25,26)(27,33)(28,37)(29,31)(30,34)(32,36)(35,40)(38,39)(2,7)(3,4)(6,8)(9,12)(10,15)(11,18)(13,20)(14,21)(16,22)(17,23)(19,24)(25,27,29,35)(26,30,31,39)(28,38,36,34)(32,40,37,33)(12,20)(15,22)(18,24)(21,23)(26,31)(30,39)(32,37)(33,40) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.